The National Highway Traffic Safety Administration proposed updates to the main US vehicle lighting rule that would let automated vehicles use cyan marker lamps to show an self-driving system is operating the vehicle, The Verge, Electrek, and the Federal Register reported. The notice published October 26, 2026, as document 2026-21794.

NHTSA said cyan would give police and other road users a consistent blue-green signal. The lamps would be optional for makers, but any that install them would have to follow federal rules on color, brightness, and placement. The proposal also would drop some lighting rules that make little sense without a human driver.

Comments should be submitted no later than November 25, 2026, the Federal Register said. Operators such as Waymo, Nuro, and Zoox, and automakers including GM and Mercedes, could adopt a shared standard if the rule is finalized. Electrek noted a 30-day comment window under docket NHTSA-2026-1519.

The Verge said years of debate over text, sound, or custom lights led to a single proposed color. The notice also seeks input on related lighting flexibility for vehicles built without steering wheels or pedals.

States already run a patchwork of rules on robotaxi lights and signs. A federal color would cut that mix if makers opt in. NHTSA also asked whether other lighting rules should bend for cars built without manual controls.

Cyan is a blue-green hue meant to stand out at night. Makers would not have to add the lamps. If they do, the federal look would match.

What we know: NHTSA proposed optional cyan ADS marker lamps. Comments close November 25, 2026.
What we don't: Whether the rule will be finalized as proposed, and when fleets would add the lamps.